<template>
    <el-breadcrumb
        class="app-breadcrumb"
        separator="/"
    >
        <transition-group name="breadcrumb">
            <el-breadcrumb-item
                v-for="(item,index) in levelList"
                :key="item.path"
            >
                <span
                    v-if="item.redirect==='noRedirect'||index==levelList.length-1"
                    class="no-redirect"
                >{{ item.meta.title }}</span>
                <a
                    v-else
                    @click.prevent="handleLink(item)"
                >{{ item.meta.title }}</a>
            </el-breadcrumb-item>
        </transition-group>
    </el-breadcrumb>
</template>

<script>
import pathToRegexp from 'path-to-regexp'
export default {
	data() {
		return {
			levelList: null
		}
	},
	watch: {
		$route(route) {
			// if you go to the redirect page, do not update the breadcrumbs
			if (route.path.startsWith('/redirect/')) {
				return
			}
			this.getBreadcrumb()
		}
	},
	created() {
		this.getBreadcrumb()
	},
	methods: {
		getBreadcrumb() {
			// only show routes with meta.title
			let matched = this.$route.matched.filter((item) => item.meta && item.meta.title)
			const first = matched[0]
			if (!this.isDashboard(first)) {
				matched = [{ path: '/dashboard', meta: { title: '首页' } }].concat(matched)
			}
			this.levelList = matched.filter((item) => item.meta && item.meta.title && item.meta.breadcrumb !== false)
		},
		isDashboard(route) {
			const name = route && route.name
			if (!name) {
				return false
			}
			return name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
		},
		pathCompile(path) {
			// To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
			const { params } = this.$route
			var toPath = pathToRegexp.compile(path)
			return toPath(params)
		},
		handleLink(item) {
			const { redirect, path } = item
			if (redirect) {
				this.$router.push(redirect)
				return
			}
			this.$router.push(this.pathCompile(path))
		}
	}
}
</script>

<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
	display: inline-block;
	font-size: 14px;
	line-height: 50px;
	margin-left: 8px;
	.no-redirect {
		color: #97a8be;
		cursor: text;
	}
}
</style>